Roles for phosphoinositide 3-kinases, Bruton's tyrosine kinase, and Jun kinases in B lymphocyte chemotaxis and homing

Eur J Immunol. 2006 May;36(5):1285-95. doi: 10.1002/eji.200535799.

Abstract

B lymphocyte chemokine receptors signal to downstream effectors by activating heterotrimeric G proteins. However, many of these effectors remain unknown and the known ones often have ill-defined roles in B cell trafficking. Here we report that pharmacological inhibitors of phosphoinositide 3-kinases (wortmannin, WMN), Bruton's tyrosine kinase (LFM-A13), and Jun kinases (SP600125) all significantly impair CXCL12-induced mouse B cell chemotaxis and that of a human B lymphoma cell line. Examination of two CXCR4-induced signaling pathways revealed that LFM-A13 and WMN blocked Akt activation, while SP600125 and WMN blocked JNK activation. Each of the inhibitors impaired the homing of transferred B cells to peripheral lymph nodes. Intravital imaging of control and inhibitor-treated mouse B cells in the inguinal lymph node high endothelial venules (HEV) demonstrated a 17%, 35%, and 60% reduction in the number of firmly adherent B cells with LFM-A13, SP600125, and WMN, respectively. These results implicate chemokine receptor mediated activation of phosphoinositide 3-kinases in the firm adhesion of mouse B cells within peripheral lymph node HEV, while Bruton's tyrosine kinase and JNK activation are less important and more likely needed during B cell transmigration through the endothelium and/or trafficking into the lymph node parenchyma.

MeSH terms

  • Agammaglobulinaemia Tyrosine Kinase
  • Amides / pharmacology
  • Androstadienes / pharmacology
  • Animals
  • Anthracenes / pharmacology
  • B-Lymphocytes / immunology
  • B-Lymphocytes / physiology*
  • Calcium / metabolism
  • Cell Movement*
  • Chemokine CXCL12
  • Chemokines, CXC / pharmacology
  • Chemotaxis, Leukocyte*
  • Female
  • JNK Mitogen-Activated Protein Kinases / physiology*
  • Mice
  • Mice, Inbred C57BL
  • Nitriles / pharmacology
  • Phosphatidylinositol 3-Kinases / physiology*
  • Protein-Tyrosine Kinases / physiology*
  • Wortmannin

Substances

  • Amides
  • Androstadienes
  • Anthracenes
  • CXCL12 protein, human
  • Chemokine CXCL12
  • Chemokines, CXC
  • Cxcl12 protein, mouse
  • LFM A13
  • Nitriles
  • pyrazolanthrone
  • Phosphatidylinositol 3-Kinases
  • Protein-Tyrosine Kinases
  • Agammaglobulinaemia Tyrosine Kinase
  • Btk protein, mouse
  • JNK Mitogen-Activated Protein Kinases
  • Calcium
  • Wortmannin